Which muscles are considered the primary muscles of mastication?

The primary muscles of mastication include the masseter, temporalis, medial pterygoid, and lateral pterygoid. These muscles are crucial for the process of chewing, each playing a specific role in the complex movement of the jaw.

The masseter is primarily responsible for elevating the mandible, thereby closing the jaw during chewing. The temporalis, located on the side of the head, also assists in elevating the mandible and helps with retracting it. The medial pterygoid works alongside the masseter to elevate the jaw, and it also allows for lateral movement of the mandible. The lateral pterygoid, in contrast, is essential for opening the jaw and aids in repositioning it from side to side, making it integral for the grinding motion required during mastication.

Other options presented include muscles that are not primarily involved in chewing or serve different functions, such as facial expression or neck movement. For instance, the zygomaticus and buccinator are involved in facial expressions rather than mastication, while the digastric muscle primarily serves to depress the mandible.